In 2017 Patently Apple made the call that smart fabric and clothing was becoming a trend of R&D at Apple as a number of patents began to make their way to the public. To date we've covered 37 patents on this single theme that could be reviewed in our special archive. According to GlobalData, garments and footwear with integrated sensors that transmit biometric information and other datasets will reach new heights of popularity by 2030 and is set to be worth over $4bn.

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Yesterday the U.S. Patent Office published a patent application that relates to stretchable materials and signal path structures for future electronic devices.

Apple's invention covers future devices and accessories like an Apple Watch band that will use smart fabric technology with stretchable fabric signal paths. A stretchable fabric signal path may include one or more conductive strands located between first and second outer fabric layers. The outer fabric layers may be formed from intertwined strands of elastic material. The conductive strand may have a wavy shape to accommodate stretching of the stretchable fabric signal path.

One or more inner fabric layers may be located between the outer stretchable fabric layers. The inner fabric layers may be formed from intertwined strands of non-elastic material. The inner fabric layers may have strands that are intertwined with the outer fabric layers to serve as anchor points for maintaining the shape of the conductive strand as the stretchable fabric signal path expands and contracts. The outer fabric layers and inner fabric layers may be woven.

The conductive strand may convey electrical signals such as audio signals, power signals, data signals, or other suitable signals. The conductive strand may form floats on the inner fabric layers. In some arrangements, a first float on a first inner fabric layer may at least partially overlap a second float on a second inner fabric layer.

To create overlapping floats in this way, the conductive strand may turn back on itself between the first and second inner fabric layers. The additional length in the conductive strand needed to make these turns may help increase the amount by which the conductive strand can stretch.

Apple's patent FIG. 1  below illustrates a schematic diagram of electronic equipment that may be provided with stretchable fabric signal path structures; FIG. 2-4 represents devices such as earphones, a car seat and Apple Watch band that could one day use stretchable fabrics with integrated signal paths. 

Apple's patent FIG. 10 above illustrates cross-sectional side views of illustrative stretchable fabric signal paths having elastic strands, non-elastic strands, and one or more conductive strands.

Apple's patent FIG. 12 below illustrates how the shape of the strands in stretchable fabric signal path (#18) may change under different amounts of stretch. At the top of FIG. 12, the signal path is stretched to its maximum length L1. Apple's patent FIG. 12 then shows the signal path contracting to progressively shorter lengths until it reaches its minimum length L2 shown at the bottom of the image.

For finer details, review Apple's patent application number 20210087719.

Daniel Podhajny is listed on the patent as one of the inventors. Podhajny came to Apple via Nike's Knit Exploration Innovator as part of the teams who worked on Flyknit technology. This adds credibility and seriousness to this patent and project. In total, 10 engineers and designers are credited for this invention/patent.

Considering that this is a patent application, the timing of such a product to market is unknown at this time.